In addition to the local anesthetic, a subconjunctival injection is desirable to anesthetize the iris. This is best done under the superior rectus muscle, so as not to obstruct the area of section. A retrobulbar injection is used by many surgeons to anesthetize the ciliary ganglion. This increases the anesthesia of the eyeball and often weakens the action of the inferior rectus muscle, which is desirable, as the turning down of the eyeball during the intracapsular operation is not without danger. The retrobulbar injection may cause a softening of the eyeball, which in the opinion of many surgeons is favorable, as it reduces the tendency to prolapse of the vitreous. If this softening is extreme, however, the proper conduct of the operation may be interfered with; so it is best to give the injection just before the operation. To avoid hemorrhage into the orbit, this injection should be made close to the eyeball, and not deep into the orbit.
A look at the past . . .. Arch Ophthalmol. 2000;118(7):923. doi:10-1001/pubs.Ophthalmol.-ISSN-0003-9950-118-7-eya00008